Abstract

Soluble guanylate cyclase (sGC), the receptor for nitric oxide, is a heterodimer consisting of α and β subunits. We investigated the mRNA species for the α1 subunit in human brain, heart, artery and immortalized B-lymphocytes. Three mRNA species were identified in these tissues. The major mRNA species contained the full expression sequence of the α1 subunit. Two other types of mRNA were detected in which 5ʹ sequences were deleted by splicing (506-590 and 412-590). Each of these deletions included the predicted translation start site, indicating that translation of these two alternatively spliced RNA species does not result in the production of full-length α1 subunits. The relative amounts of the two mRNA species with deletions of the translation start site differed significantly between cell lines of immortalized B-lymphocytes from different individuals. sGC enzymic activity was significantly decreased in cellular extracts from cell lines with high proportions of mRNA species containing the deletion 506-590 when compared with extracts from cell lines that contained mostly mRNA without this deletion.